"This is to fix a problem before it becomes a problem. This will make things safer," he said.

Glitches in iOS 7, Apple's new operating system which launched on Wendesday, have already been spotted.

Videos posted online showed users circumventing the lock via the control centre – a new feature of iOS 7.

The hacker can then access photos as well as the owner's email, Facebook and Twitter accounts, it has been claimed.

Apple spokeswoman Trudy Muller told technology website AllThingsD: "Apple takes user security very seriously. We are aware of this issue, and will deliver a fix in a future software update.”

Concerns over the ability of people to track down stolen iPhones have also surfaced after another flaw in the system was discovered.

Apple's 'Find my iPhone' app can effectively be deactivated by thieves who can switch the device to airplane mode without unlocking the phone, thereby cutting off the handset's signal and internet access.

The iOS was released two days ago and has been hailed by Apple executives as a major step forward, with chief executive Tim Cook calling it “the biggest change to iOS since the iPhone”.

Craig Federighi, Apple’s senior vice president of Software Engineering, said downloading iOS 7 would be "like getting a brand new device, but one that will still be instantly familiar to our users".

The technology will come preloaded on iPhone 5s and 5c – on sale today – while UK users with old Apple devices were able to download it from 6pm on Wednesday.

However users reported long delays as thousand of people attempted to download the new software, with some posting screen shots on social networking sites showing predicted times of more than 24 hours before completion.

The technique for getting around the lock screen appears to work on old devices like the iPhone 4 and 5 but it is not known if the same applies to the new iPhones.

Fans have been queuing for days to be the first to get their hands on the iPhone 5s, which features fingerprint technology, and the iPhone 5c, which comes in a range of bright colours and is the cheaper of the two.

The iPhone 5s costs £549 for the 16GB model, £629 for the 32GB model and £709 for the 64GB model, while the "budget" 5c costs from £469 for the 16GB model and £549 for the 32GB model.